They usually keep an eye on you even if you can't see them around, I saw this one and his mate looking for food in my backyard so I went out, tossed a few grapes where they were looking, and left the rest of the bowl on my step. Saw this one chowing down by the time I was back inside
Try visibly eating them in front of them and then drop them on the ground and walk away. They might follow your cue.
They usually keep an eye on you even if you can't see them around, I saw this one and his mate looking for food in my backyard so I went out, tossed a few grapes where they were looking, and left the rest of the bowl on my step. Saw this one chowing down by the time I was back inside